Design and control of permanent magnet assisted synchronous reluctance motor with copper loss minimization using MTPA

It is necessary to find the suitable d - and q -axis reference currents to control PMA-SynRM motors with high efficiency. This paper presents the maximum torque per ampere (MTPA) to minimize the copper losses of the system and utilizes the field weakening control to operate above the rated speed of the PMA-SynRM. The copper losses equation and electromagnetic torque are used to optimize the d - and q -axis current references. A small-scale 1 kW prototype PMA-SynRM was designed and manufactured to test and examine the proposed control in the laboratory. The proposed algorithm was digitally carried out using the MicroLab Box dSPACE. The simulation results show that the copper losses of the machine with the MTPA algorithm are lower than those without the MTPA algorithm. The PMA-SynRM operates above the base speed of ~ 70 % in the constant power region by mean of field weakening control.